package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //1.判断是否关注\
        //1.1.获取当前用户
        String userId = UserHolder.getUser().getId();
        if (isFollow){

            //1.2.保存数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);

            boolean isSuccess = save(follow);
            if (isSuccess){
                //1.3.保存数据到redis
                String key = "follow:" + userId;
                stringRedisTemplate.opsForSet().add(  key,followUserId.toString());
            }
        }else {
            remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));

            //把关注移除
            stringRedisTemplate.opsForSet().remove("follow:" + userId,followUserId.toString());
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        String userId = UserHolder.getUser().getId();
        //1。查询是否 关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();

        //3.判断
        return  Result.ok(count() > 0);
    }

    @Override
    public Result followCommons(Long id) {
        //1.获取当前用户
        String userId = UserHolder.getUser().getId();
        String key = "follow:" + userId;
        //2.求交集
        String key2 = "follow:" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect == null || intersect.isEmpty()){
            //没有交集
            log.info("没有交集");
            return Result.ok(Collections.emptyList());

        }
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());

        //4.根据id查询用户
        List<UserDTO> userDTOS = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
